having some fun with the new gsl egg
get rid of all the hand-optimized code in sift-match, naive code with the gsl egg exceeds its performance

For reference:
|    time | relative | method                |
|   0.440 |       1x | C                     |
|   0.618 |   1.404x | gsl dot_sub           |
|   0.731 |   1.661x | gsl dot_axpy          |
|   1.508 |   3.409x | gsl sub3 & dot        |
|   4.073 |   9.256x | gsl v- & dot          |
|   4.668 |  10.609x | hand-optimized scheme |
| 148.881 |     338x | scheme v- & dot       |